Abstract: Three 2-hydroxy naphthaldehyde phenyl hydrazone derivatives were designed and synthesized (1-3; substituent R = p-H, p-NO2, 2, 4-(NO2)2). The interaction between the target compounds and anions was investigated by means of a UV spectrometer, and the effect of the affinity and selectivity of receptors to anions was also studied by changing the N’-substituted groups of benzene ring. The result showed that absorption spectra of receptors were red shifted significantly in acetonitrile solution containing F－and CH3COO－, and a clear color change was observed from yellow to blue or red in acetonitrile solution. The receptor molecule 2 had high selectivity and sensitivity response to F－ and will promise to a good sensing molecule in detection of F－by naked eye. The recognition selectivity of receptor molecule 3 to anion can be changed through adding water in acetonitrile solution, and receptor molecule 3 only recognized F－in 5％H2O-95％ CH3CN(V/V) solution, but had no evident response to other anions. So receptor molecule 3 is expected to be a new sensor which can recognize F－by naked eye in aqueous solution.

Key words: 2-hydroxynaphthaldehyde phenyl hydrazone, fluoride anion, selectivity, naked eyes